FastWhisper.Client 1.0.0

FastWhisper.Client

A clean, minimalistic .NET client library for the FastWhisper API.

Features

• Simple and intuitive API
• Async/await support
• Full coverage of FastWhisper API endpoints:
  • Health check
  • Audio transcription
  • Audio translation to English
• Configurable timestamp granularity (chunk or word level)
• Language detection and specification
• Modern .NET 9.0 with nullable reference types
• Minimal dependencies

Installation

dotnet add package FastWhisper.Client

Quick Start

using FastWhisper.Client;
using FastWhisper.Client.Models;

// Create client
using var client = new FastWhisperClient("http://127.0.0.1:8000");

// Check health
var health = await client.GetHealthAsync();
Console.WriteLine($"Status: {health.Status}, Model Loaded: {health.ModelLoaded}");

// Transcribe audio
await using var audioStream = File.OpenRead("audio.mp3");
var transcription = await client.TranscribeAsync(
    audioStream,
    "audio.mp3",
    language: "en",
    timestamp: TimestampGranularity.Chunk
);

Console.WriteLine($"Text: {transcription.Text}");
foreach (var chunk in transcription.Chunks)
{
    Console.WriteLine($"[{chunk.Timestamp[0]:F2}s - {chunk.Timestamp[1]:F2}s]: {chunk.Text}");
}

API Reference

Health Check

var health = await client.GetHealthAsync();

Transcribe Audio

Transcribes audio to text in the original language.

var transcription = await client.TranscribeAsync(
    audioStream,
    fileName: "audio.mp3",
    language: "en",                            // Optional: null for auto-detect
    timestamp: TimestampGranularity.Chunk,     // Chunk or Word
    cancellationToken: cancellationToken
);

Translate Audio

Translates audio to English text.

var translation = await client.TranslateAsync(
    audioStream,
    fileName: "audio.mp3",
    timestamp: TimestampGranularity.Word,
    cancellationToken: cancellationToken
);

Timestamp Granularity

• TimestampGranularity.Chunk (default): Segment-level timestamps (phrases/segments)
• TimestampGranularity.Word: Word-level timestamps (finer granularity)

Language Codes

Supported language codes (ISO 639-1): en, fr, es, de, it, pt, nl, ja, zh, etc.

Pass null to the language parameter for automatic language detection.

HttpClient Management

Default Usage

using var client = new FastWhisperClient("http://127.0.0.1:8000");

Custom HttpClient

For dependency injection or custom configuration:

var httpClient = new HttpClient
{
    BaseAddress = new Uri("http://127.0.0.1:8000"),
    Timeout = TimeSpan.FromMinutes(5)
};

var client = new FastWhisperClient(httpClient, disposeHttpClient: false);

Error Handling

try
{
    var transcription = await client.TranscribeAsync(audioStream, "audio.mp3");
}
catch (HttpRequestException ex)
{
    Console.WriteLine($"API request failed: {ex.Message}");
}
catch (InvalidOperationException ex)
{
    Console.WriteLine($"Response parsing failed: {ex.Message}");
}

License

MIT License - see LICENSE file for details.

Related Projects

• FastWhisperApi - The FastWhisper API server
• faster-whisper - Fast Whisper inference (SYSTRAN)